What is a person trying to achieve if they draw a circle within a circle, the inner circle having a radius (x) that is derived from the radius of the outer circle (y) using the formula x=y(SIN(x))?
2007-04-07 11:18:39 · 4 answers · asked by Robert W 1 in Science & Mathematics ➔ Mathematics
sorry - that should read x=y(sin(45DEG))
2007-04-07 11:21:18 · update #1
OK - this is a sphere with a radius of 10mm. It's skin is 1mm thick. It is being cut into two interlocking "C" shapes which will be re-assembled to make another sphere (like a tennis ball). The "blade" tool that is being used to cut the sphere is formed from an arc and two straight lines. The arc is using the centre point of the sphere and has this formula as its radius. It works - but I'm trying to work out how I should know to be able to do this.
2007-04-07 11:36:04 · update #2
That makes the area between the circles equal to the area of the inner circle.
Outer circle has area pi*y^2.
Inner circle has area pi*x^2
= y^2sin^2(45deg)
= (y^2)/2
Area between circles = (y^2)/2.
2007-04-07 11:28:26 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Sounds like they're trying to "achieve" the radius of the inner circle, but without a diagram or more information it's kinda hard to know why they're using that formula.
2007-04-07 18:23:51 · answer #2 · answered by Philo 7 · 0⤊ 0⤋
The inner circle has a radius of 70.7% of the outer circle, a circumference of 70.7% of the outer circle, and an area of 50% of the outer circle.
The person is dividing the area of the outer circle into two equal parts.
2007-04-07 18:31:38 · answer #3 · answered by morningfoxnorth 6 · 0⤊ 0⤋
Lookslike they are trying to draw a tyre.
Sorry for the flippant answer, but I don't think that there is enough information to work out what the mathematical background to this is.
2007-04-07 18:25:12 · answer #4 · answered by mathsmanretired 7 · 0⤊ 0⤋